Blunder, tucking into regional cheese after the Spanish fruity wine? (10)
I believe the answer is:
elderberry
'fruity wine?' is the definition.
'blunder tucking into regional cheese after the spanish' is the wordplay.
'blunder' becomes 'err' (I've seen this before).
'tucking into' means one lot of letters goes inside another.
'regional cheese' becomes 'derby'.
'after' says to put letters next to each other.
'the spanish' becomes 'el'.
'err' placed into 'derby' is 'derberry'.
'derberry' put after 'el' is 'ELDERBERRY'.
(Other definitions for elderberry that I've seen before include "Wine or jelly can be made from this" , "Fruit used for home-made wine" , "Fruit used for jelly or wine" , "Fruit used for cordial" , "A blue-black fruit" .)